JOHN FINLAY MINING中文JOHN FINLAY MINING中文Slime-heavy ores defeat many sorting technologies — dense medium cyclones handled this one at 2.7× uplift; a joint overseas laboratory is now in negotiation.
| Product | Yield % | Grade % | Recovery % |
|---|---|---|---|
| Concentrate | 30.05 | 4.31 | 82.49 |
| Rejects | 69.95 | 0.393 | 17.51 |
| Feed | 100 | 1.57 | 100 |
Unlike optical or flotation routes degraded by slime coatings, density separation in a cyclone is indifferent to surface condition — the medium reads mass, not appearance.
This chalcopyrite ore, submitted by a Shenyang research institute, carries an unusually high slime content — the failure mode for most sorting technologies. Slime coatings blind optical sorters and NIR sensors, and in flotation they consume reagent and dilute concentrates. The question the institute posed: can any pre-concentration stage survive this feed?
The answer was a 2.7× enrichment (1.57% → 4.31% Cu) at 82.49% recovery, with 69.95% of the mass rejected. Two numbers matter beyond the headline: rejects at 0.393% Cu confirm the cut density was placed correctly against the composite-particle population, and the campaign's repeatability across slime-heavy sub-samples is what convinced the institute the mechanism is genuinely surface-independent.
| Item | Value |
|---|---|
| Feed size fraction | 0.5–10mm |
| Separator | Pressurized two-product dense medium cyclone |
| Medium | Ferrosilicon + magnetite powder, closed-circuit recovery |
| Density control | In-line density gauge with automatic water/medium make-up loop |
| Value mineral density | Chalcopyrite: 4.1–4.3 g/cm³ |
| Gangue density | Silicate gangue: 2.6–2.7 g/cm³ |
| Process water | 0.1 m³/t, fully recirculated |
| Medium drainage | Sieve bends + drain-and-rinse screens |
The ore was first wet-screened to remove the −0.5 mm slimes (evaluated separately for flotation). The 0.5–10mm fraction was fed to a ferrosilicon/magnetite suspension; a density-gradient series located the optimum cut density, after which the sample was passed once through a pressurized two-product cyclone. Products were drained on sieve bends, rinsed on drain-and-rinse screens, dewatered, sampled and assayed to compute yield, grade and recovery. Dilute medium was recovered by magnetic separation and densified back to the correct-medium sump under closed-loop density control.
The collaboration has moved beyond the test report: we are negotiating a jointly-built overseas dense-medium laboratory with the institute — pairing their research pipeline with our operating flowsheets, and giving both sides a permanent test bench for slime-tolerant pre-concentration.
Q: What recovery did dense medium separation achieve on this copper ore?
A: 82.49% Cu recovery into a 4.31% concentrate on high-slime ore, 69.95% of mass rejected (0.5–10 mm).
Q: Will this work on my copper deposit?
A: Density separation depends on liberation size and density contrast, not on locality. A one-tonne representative sample answers the question definitively — washability results within 24 hours of sample receipt.
Send ~1 tonne of representative ore — washability results within 24 hours of sample receipt.
Contact us